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/* * Copyright 2002,2004 The Apache Software Foundation. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.apache.commons.jelly.expression; import org.apache.commons.jelly.JellyContext; /** <p><code>ConstantExpression</code> represents a constant expression.</p> * * <p> In other words, {@link #evaluate} returns a value independent of the context. </p> * * @author <a href="mailto:jstrachan@apache.org">James Strachan</a> * @version $Revision: 1.9 $ */ public class ConstantExpression extends ExpressionSupport { /** The value of this expression */ private Object value; /** Base constructor */ public ConstantExpression() { } /** Convenience constructor sets <code>value</code> property. */ public ConstantExpression(Object value) { this.value = value; } public String toString() { return super.toString() + "[value=" + value + "]"; } public String getExpressionText() { return value == null ? "null" : value.toString(); } /** * Evaluate expression against given context. * * @param context evaluate expression against this context * @return current value of <code>value</code> property */ public Object evaluate(JellyContext context) { return value; } /** Gets the constant value of this expression */ public Object getValue() { return value; } /** Sets the constant value of this expression */ public void setValue(Object value) { this.value = value; } }